The present invention pertains to novel thermosettable compositions.
Thermosettable compositions such as unsaturated polyester resins, dicyclopentadiene modified unsaturated polyester resins, unsaturated polyesteramide resins, dicyclopentadiene modified unsaturated polyesteramide resins, vinyl ester resins and the like are well known. Such resins can be employed as is, but are usually diluted with a polymerizable unsaturated monomer such as styrene. These resins are useful in the preparation of castings, laminates, coatings, and the like. However, such resins create relatively large exotherms upon curing, usually with peroxide curing agents, which can induce cracking or fracturing of the cured part, as well as excessive volatile monomer loss.
The present invention provides a thermosettable resin composition which has reduced exotherm temperatures without an unacceptable low in reactivity rate and in many instances, the cured resin has an improvement in one or more properties such as heat distortion temperature, hardness, tensile strength, elongation, resistance to thermal aging and the like.